oxide layer in SOI substrates; oxide (SiO2) buried in silicon wafer at the depth ranging from less than 100 nm to several micrometers from the wafer surface depending on application; thickness of BOX is typically in the range from about 40 nm to about 100 nm.

bonded SOI

SOI substrates formed by bonding two silicon wafers with oxidized surfaces; following bonding one wafer is polished down to the desired thickness of active layer with interface oxide becoming a buried oxide.

SIMOX,

Separation by IMplantation of OXygen; common method used to fabricate SOI substrates; oxygen ions are implanted into Si substrate and form a buried oxide layer.